Cancer Flashcards
What are the 2 chromosomes related to Burkett’s Lymphoma?
Chromosome 8 & 14 translocation
What is characteristica about Burkett’s Lymphoma & what population is more susceptible?
Ch[8:14]= activated pro to-oncogene = Tumour in the jaw. Seen in Equatorial Africa.
Describe a bening mass
slow growing, no invasive.
Describe a malignant mass
fast growing invades proximal & distal tissues.
Describe Sarcoma
Mesenchymal origin i.e. bone, ct, muscle, nervous system.
Describe Carcinomas
Epithelial origin i.e. cell lining intestine, bronchi, mammary ducts.
Describe hematopoetic & Lymphoid
bone marrow & lymph nodes.
What is require to deactivate a tumor suppressor gene?
a 2 hit mechanism.
What is special about a Proto-oncogene?
It only requires a single mutation to go from normal to malignant.
What are the 2 chromosome involve in CML?
Chromosome 22 & 9 (Philadelphia Chromosomes)
What is commonly use to TX CML?
Imatinib(Gleevac) tx on tyrosine residue blocks ATP signals.
Is MEN-2 AD or AR?
AD
MEN-2 represents a mutation in what gene?
RET Gene for receptor tyrosine kinase
Does MEN-2 representa a LOF or GOF mutation?
GOF Mutation
With what type of tissue and/or organs is MEN-2 associated?
Medullary carcinoma of the thyroid and Phenochromocytomas of adrenal medulla —–> Over secretion of NE and Epi —-> Increase in HR, BP etc…
What is Retinoblastoma?
Mutation of Rb on Chr. 13
What is the normal function of Rb?
Normal function of Rb is to regulate G1/S phase; its normally not phosphorylated so it binds E2F and PREVENTS transcription.
What are the 2 possible types of mutation in Rb?
In inherited retinoblastoma (dominant trait), there are multiple bilateral tumors, having an early age of onset—one Rb1 mutation is
inherited, and any mutation in the second allele would leadto cancer.
or
In sporadic retinoblastoma, there are single unilateral tumors, having a late age of onset—two “hits” of the Rb1 mutation need to take place.
What are the 2 types of tumor suppressor genes?
- Gatekeeper = regulate proto-oncogene function. **Regulate various cell cycle points. Also regulate apoptosis.
- Caretakers = Act more indirectly by maintaining genome integrity. **Correct mutations during DNA replication & Cell division.
Is Li-Fraumeni AR or AD mutation?
AD
What is mutated in Li-Fraumeni Syndrome?
Ch 17 –> TP53 a transcription factor that induces the synthesis of P21 use in cell cycle arrest.
How is TP53 active?
when phosphorylated
What is the function of Mdm2?
it inhibits TP53 by keeping it in the cytoplasm, so it doesn’t activate P21.
With what type of cancer is BRCA1 associated with?
BRCA1 on Ch 17 is associated with Breast and Ovarian cancer. Through the ATM cell cycle arrest pathway.
With what type of cancer is BRCA2 associated with?
BRCA2 on Ch 13 is associated with Breast cancer, gallbladder, pancreatic, male breast cancer.
Are BRCA 1 & 2 oncogenes or tumor suppressor?
Tumor suppressors
What are the type of inheritance? Mutation? Chromosome? associated with Familial Adenomatuous Polyposis (FAP)?
AD
Mutation in APCgene
Chromosome 5
What is the function of APC?
The normal function = gatekeeper (binding beta catenin to phosphorylate
and degrade; stops its oncogene activity) mutated APC = uncontrolled
beta catenin activity and c-myc transcription
What is FAP?
Develop colon cancer by age 40. It starts with THOUSANDS of benign polyps in large intestine =
predisposition for cancer.
What is HNPCC?
Hereditary Non Polyposis Colon Cancer - Colon-rectal Cancer
What is the mode of inheritance in HNPCC?
AD
What is the defect in HNPCC?
Defect in DNA MisMatch Repair of normal tumor suppressor genes:
MLH1
MSH2
MSH6
Microsatellite Instability: from RER+ phenotype
What is Xeroderma Pigmentosa?
AR mutation. Ineffective nucleotide excision repair, UV light produce thymine dimers can’t be fixed.
What is Bloom Syndrome?
chromosomes instability
What are some of the possible clinical manifestations of Xeroderma Pigmentosa?
Skin cancer, cataract, neurological abnormalities etc…
What are some of the possible clinical manifestations of Bloom Syndrome?
growth deficiency, immune deficiency and increased cancer.
What is Ataxia telangiectasia?
AR chromosome instability. Causes Cerebellar ataxia and telangiectases
What is Fanconi Anemia?
Mutation in 8 different loci; chromosomes instability. Can cause Anemia and Leukemia.
What does Fanconi, Ataxia Telangiectasia, Bloom and Xeroderma have in common?
They are all Caretaker genes.
Whats and example of an inherited oncogene that may cause cancer?
RET gene —-> MEN-2
